Sinuous spring for cushion construction



Dec. 14, 1954 A. v. HANDREN, JR 2,696,871

SINUOUS SPRING FOR CUSHION CONSTRUCTION Filed May 26, 1950 INVENTOR.

United States Patent O 2,696,871 SINUOUS SPRING FOR CUSHION CONSTRUCTION Arthur V. Handren, Jr., Birmingham, Mich., assignor to No-Sag Spring Company, Warren Township, Mich., a corporation of Michigan Application May 26, 1950, Serial No. 164,480 2 Claims. (Cl. 155-179) This invention relates to spring constructions, and particularly to a spring assembly which provides a soft edge to a seating surface and offers resistance to the downward deflection thereof.

Sinuous spring strips made of wire bent back and forth to provide oppositely presenting adjacent loop portions joined by straight portions have been used in cushion constructions for quite some time. The spring strip is formed on an arc of substantially small radius to provide inherent resistance against downward deflection when the ends are extended and secured to a frame. Substantial stress was applied to the frame by the force set up in the arched springs when the ends were extended to span the frame and it was diflicult to provide a soft edge construction along the edge of the frame.

The present invention pertains to the use of a U-shaped sinuous spring element which has one end anchored adjacent to the end of the sinuous spring strip so that the stresses in the load-supporting spring strips of the assembly may be resisted by the U-shaped element when its free end is anchored to the frame and the opposite end of the main spring strip is secured to the opposite side of the frame. This produces the desired contour to the the same time provides a soft edge at the front of the assembly. To prevent the forward and rearward movement of the assembly, the rear end of the main spring strip may be bent downwardly to abut the inner face of the rear frame element.

Accordingly, the main objects of the invention are: to provide a spring assembly made of a main spring strip of arcuate form and a U-shaped spring element which is rigidly anchored near the end thereof; to form a spring assembly from a spring strip which is set on an arc of small radius by securing near one end thereof a U-shaped element and having the opposite end deflected at a substantial angle; to provide a U-shaped sinuous spring element having arcuate sides which are substantially parallel extending from one of the loops of the spring strip and rigidly anchoring one of its ends to the end of an arcuate spring strip and pivotally securing its opposite end to the frame, and, in general, to provide a spring assembly which is simple in construction and which is readily attachable to a frame.

Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawing, wherein:

Figure 1 is an elevational view of the spring assembly of the present invention when applied to a frame;

Fig. 2 is a broken plan view of a front corner of the assembly illustrated in Fig. 1;

Fig. 3 is a perspective View of the rear portion of the assembly illustrated in Fig. 1, as viewed from the point 3 thereof;

Fig. 4 is an enlarged view of the soft edge spring element before being stressed in assembly, and

Fig. 5 is a view of the spring assembly before being attached to the frame.

Referring to the figures, the spring assembly embodies a sinuous spring strip 11 which in its free state is of arcuate form along its longitudinal dimension, as illustrated in dot and dash line in Fig. 1 and as illustrated in Fig. 5. The sinuous spring strips have adjacent oppositely disposed loops 12 and 13 which are joined by straight portions 14. The are of small radius provided longitudinally of the length of the spring strip 11 offers resistance against downward deflection and the hammock effect which would occur if a straight strip were anchored at the ends across the frame. A spring element 16, which may be of the same gauge or heavier gauge wire than that of the spring strip 11, is formed to have a projecting arm 17 and a shorter anchoring arm 18 extending from a loop 20. The end 17 of the spring 16 is secured to the straight portions of the next ad acent end loop of the spring strips 11 by suitable clamplng bands 22 to securely attach the two spring elements together against any pivotal movement. "lhe arms 17 and '18 are substantially parallel in the free state, as illustrated in big. 4, and are moved into angular relation to each other when the end of the arm 18 and the free end of the spring 11 are secured to the frame elements l9 and 21.

The end of the portion 18 is secured by a suitable clip 23 to the frame element 19 and the opposite end of the strip 11 is stretched across the frame and secured by a clip 23 to the frame element 21. in view of the arcuate form of the strip 11, considerable force is exerted when drawing the end across the frame and the resulting stress is taken longitudinally of the arm 17 of the spring element 16. "lo prevent the pivoting of the spring 11, an end portion 2:) thereof at the rear end of the strip is deflected downwardly substantially at right angles to the strip for abutment against the inner face of the frame member 21, thereby preventing the rotation of the straight end portion of the spring within the clamp 23 and the front end of the spring from rocking upwardly. The end portion 25 causes the deflection or the spring 11 to be downwardly, with the front edge portion being spring supported to provide a soft edge.

The straight portions of the front projecting loops 0 the springs 11 are attached to a border wire 26 by bands 22. By using a U-shaped spring 16 which has sides 17 and 18 which are disposed substantially parallel, the spring portion 11 may be formed on a substantial arc and still offer resistance against downward deflection when extended across the frame. The spring elements 16 may be constructed of different gauge wire from that of the spring strip 11 and preferably made of heavier gauge in view of the resistance which it must provide against deforming when the spring strip 11 is stretched to a desired form across the frame.

What is claimed is:

l. A spring unit including a sinuous spring strip formed on an arc of smaller radius than the arc thereof when the ends are extended and secured to dispose the strip in seating position, a U-shaped spring element having a pair of extending arms projecting toward one end of the strip, and means for rigidly securing the end of one arm against and directly to said strip spaced inwardly from said end thereof, the opposite end of said spring strip having a loop thereof deflected at an angle from the adjacent arcuate portion inwardly thereof.

2. A spring element made of wire bent back and forth to form adjacent oppositely presenting loops joined by straight portions, and a U-shaped spring element made of wire in a similar manner having the loop of one end secured rigidly to a loop adjacent to the end of said first spring element, the gauge of the wire of said second spring element being greater than the gauge of the wire from which said first spring element was made, the opposite end of the first said spring element being deflected inwardly at an angle to the adjacent arcuate portion.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,124,655 Freund July 26, 1938 2,214,136 Hopkes Sept. 10, 1940 2,239,062 Tallmadge Apr. 22, 1941 2,364,499 Wolofski Dec. 5, 1944 2,480,667 Neely Aug. 30, 1949 2,526,183 Williams et al. Oct. 17, 1950 2,571,184 Bateman et al Oct. 16, 1951 2,591,185 Neely Apr. 1, 1952 2,593,831 Bank Apr. 22, 1952 FOREIGN PATENTS Number Country Date 28,617 Great Britain 1912 

